Casing-tongs.



W. LEWIN.

CASING TONGS.

APPLIOATION FILED P1113114, 1911.

1,008,654. Patented Nov. 14, 1911.

72y m zfwm/ BY M ' ATTORNEYS,

COLUMBIA PLANOGRAPH co., WASHINGTON, n. c.

STATES AE FIG WALTER LEWIN, OF COALINGA, CALIFORNIA.

GASING-TONGS.

Specification of Letters Patent.

Patented Nov. 14, 1911.

Application filed. February 14, 1911. Serial No. 608,519.

oil wells.

In the drilling of wells, the hole is cased 011' with a casing which islowered into the well, as the drilling tool cuts deeper. The casingcomes in lengths or sections, and as the string of casing in the well islowered another section is screwed on to the top. The string of casingin the well is held stationary by suitable clamping means, and thesection to be added is revolved to screw it to a seat in the coupling onthe end of the string. The casing used in oil wells is generally heavyand of a' comparatively large diameter, and much energy is required toproperly screw the two lengths together. A wrench, or tongs having along handle, is

used, the end of the handle being generally 7 connected by a rope orother flexible means to a power driven crank arm. The handle of thewrench is swung backward by hand,

and is pulled forward, screwing the casing together by means of the jerkline. The circumstances of operation are such that the angle throughwhich the wrench is moved at each jerk is approximately It is evident,therefore, that the wrench or tongs should be constructed to grip thecasing at the beginning of the forward or screwing stroke so that thecasing will be turned through as large an angle as possible. In certaincircumstances it is advisable to vary the shifting of the clamping meansas tongs movein the operative or inoperative direction so that the pullon the casing when the tongs move in the backward or inoperativedirection will not be suflicient to turn the casing in that direction.

The object of the present invention is to provide casing tongs whichhave the property of clamping the casing securely at the beginning ofthe forward movement of the tongs.

Another objectof the invention is to provide casing tongs which operateto grip the casing for a slight movement of the handle of the tongs in.the forward direction.

A further object of the invention is "to providecasing tongs which maybe readily adjustable to fit any size of casing and in which the amountof movement of the gripping or clamping jaws may be varied.

With these and other objects in view, as will more fully hereinafterappear, the invention consists of certain novel features of constructionand arrangement of parts,

hereinafter fully described, illustrated in the accompanying drawingsand particularly pointed out in the appended claims, it being understoodthat various changes in the form, proportions, size and minor details ofthe structure may be made without departing from the spirit orsacrificing any of the advantages of theinvention.

Referring to the drawings: Figure 1 is a plan or top view of the tongs,part of the handle being broken away to reduce the.

size of the figure. Fig. 2 is a side view of the tongs similar toFig. 1. Fig. 3 is a detail of the bolt by which one lug on the handle issecured to the frame. Fig. 4 is a section taken through the tongs andpart of the handle on the center line.

The. tongs consists principally of the frame 2 carrying the clampingblocks 3- 1 and the handle 5 having a bifurcated end which is attachedto opposite sides of the frame 2 at one end. The frame consists of twomembers 67 which are fastened together by the pins 8 to form acomparatively rigid structure. The pins 8 are removable so that themembers 67 may be swung apart to remove the clamping blocks 34 whendesirable. The clamping blocks 3-4 are formed with circular inner faces9, of a radius corresponding to the radius of the casing. The tongs canbe adjusted to operate difierent sized casings, by removing the clampingblocks and substituting other blocks having a radius of curvaturecorresponding to the size of the casing to be screwed.

The clamping blocks 3- 1 are provided with flanges 12 around the edges,which overlie the edge of the frame 2 and hold the blocks from beingvertically displaced. Clamping block 3 is held to a seat in the frame bymeans of the screw 18 which passes through the frame and engages theblock. Bars 14 of some tough material, such as tool steel, may beinserted in the clamping blocks, with the edges projecting slightlybeyond the faces of-the blocks, to assist in handle causes the innerface 19 to press The clampingblock 4 is provided on the gripping thecasing.

rear end with a boss 15 which projects into a hole or opening in themember 7. The boss 15 is provided with a screw threaded socket to takethe screw 16, the head of which lies external to the frame in closerelation to the handle 5. The clamping block 4- is slidable in the frame2, so that the head of the screw 16 lies more or less external to theframe depending on the position of the clamping block.

The handle 5 is provided with a bifurcated end, formed of the two lugs17 which are attached to the frame 2 by pins passing through the frameand the lugs. The inner face 19 of the handle, lying between the lugs,is preferably formed on a smooth curve and so arranged that in theoperation of the tongs it contacts intermittently with the head of thescrew 16.

One of the pins 18 which connects the handle to the frame is formedeccentric or recessed at that part 20 which contacts with the handlewhen in place. This allows the handle to be moved slightly about theother pin without moving the frame and thereby varies the distancebetween the head of the screw 16 and the inner face of the handle. Thepin 18 is provided with a square head 29 which fits in a depression inthe frame 2 and holds the pin from turning. When it is desired to varythe play of the handle on this pin, it may be partly removed, turnedthrough a 90 angle and again dropped into position. This causes thehandle to engage a part of the pin having a different eccentricitythereby varying the play. The pin 18 may be placed at either of theconnections between the handle and the frame depending upon thedirection in which it is desired to screw. The outer end of the handleis provided with a ring 21 to take the jerk line or other connection. Asa means of securing a holding or lifting means for transporting thetongs, I provide the rings 2223 on the frame and handle respectively.

The operation of the device is as follows: I' will assume that the tongsare in place on the casing, and that the casing is screwed when thehandle is moved forward (Fig. 1). Under these conditions, the pin 18will connect the forward lug of the handle with the frame. The screw '16is adjusted so that when the handle is pulled forward the clampingblocks securely clamp the casing. As the handle is moved backward, theplay about the pin 18 allows the inner face of the handle to move awayfrom the head of the screw 16, and the clamping block 4 is moved awayfrom the casing so that the tongs are free to turn. At the beginning ofthe forward stroke the movement of the against the head of the screw 16,forcing the clamping block 4: into engagement with the casing. The firstslight movement of the handle, therefore, operates to clamp the casing,and the further movement of the handle turns the casing, screwing itinto the coupling. The screw 16 is adjustable so that the pressure onthe casing may be varied according to circumstances.

I claim:

1. Casing tongs, comprising a frame, clamping blocks removably fixed insaid frame, one of said blocks being slidable, a handle having abifurcated end attached to the frame at opposite corners, the connectionbetween the handle and the frame being such that the handle is capableof slight movement independent of the movement of the frame and aprojection on the slidable block adapted to contact with said'handle.

2. Casing tongs comprising a frame, a handle connected to the frame attwo points spaced apart, clamping blocks held in said frame, one of saidclamping blocks being slidable and arranged to engage the handle betweenthe two points of connection to the frame, one of said connectionsbetween the handle and the frame being loose.

3. Casing tongs comprising a frame, removable clamping blocks in saidframe, one of said clamping blocks being slidable longitudinally of saidframe, an adjustable screw in said slidable clamping block extendingthrough said frame, a handle having a bifurcated end attached to saidframe on opposite sides of said screw, the connections between thehandle and frame being loose, so that the handle has a limited movementindependent of the frame, the screw being adjusted so that it contactswith the handle between the connections.

4:. Casing tongs comprising a frame, removable clamping blocks in saidframe, one of said clamping blocks being slidable longitudinally of saidframe, an adjustable screw in said slidable clamping block extendingthrough said frame and adapted to contact with the handle, a handleattached to said frame so as to have a slight movement independent ofsaid frame and means for varying the extent of such movement.

5. Casing tongs comprising a frame, clamping blocks in said frame, oneof said clamping blocks being slidable longitudinally thereof, a screwin said slidable clamping block extending to a point external of withthe lug on the handle, said pin being said frame and adapted to contactwith the adapted to be adjusted to Vary the amount handle, a handlehaving a bifurcated end of play between the handle and the frame.

attached to said frame on opposite sides of WALTER LEWIN. said screw,one of the connections between Witnesses:

the frame and handle comprising a pin hav- A. F. WEBER,

ing an eccentric portion adapted to contact H. H. FRASER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

